Light bulb base



FIG. 1 is a top view of a light bulb base showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a right-side view thereof;

FIG. 4 is a left-side view thereof;

FIG. 5 is a back view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a perspective view thereof shown in environmental use.

The broken lines shown represent unclaimed subject matter and form no part of the claimed design. 

CLAIM I claim the ornamental design for a light bulb base, as shown and described. 